While loop in Java with examples

In the last tutorial, we discussed for loop. In this tutorial we will discuss while loop. As discussed in previous tutorial, loops are used to execute a set of statements repeatedly until a particular condition is satisfied.

Syntax of while loop

while(condition)
{
statement(s);
}

How while Loop works?

In while loop, condition is evaluated first and if it returns true then the statements inside while loop execute. When condition returns false, the control comes out of loop and jumps to the next statement after while loop.

Note: The important point to note when using while loop is that we need to use increment or decrement statement inside while loop so that the loop variable gets changed on each iteration, and at some point condition returns false. This way we can end the execution of while loop otherwise the loop would execute indefinitely.

First of all…..
The initialization done with i=0
Then goto while loop and check the condition i<4(i=0)
It is true goto the loop body execute the looping statement i.e., args[0]
Then increment the i value by 1
After incrementing again check the while loop condition …….
……
Until the condition is false.
It prints given o/p
….thats all

In for loop if the condition is true, block of statement executes first
——————
means change reflects after the completion of first iteration

In while loop if the condition is true and if it finds the increment/decrement statement in first line inside the block then it process the increment/decrement operation first and prints the output accordingly
——————
means changes reflects in first iteration itself else if the increment/decrement statement is not in first line then it is same as ‘for’ loop.
Please find the example below,
Example for loop:
class Forlooparrayexample {
public static void main(String args[]){
int a[]={1,2,3,4};
for(int i=0;i<4;++i)
{
System.out.println(a[i]);
}
}
}
output:
1
2
3
4